From patchwork Thu Apr 14 13:12:51 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 562213 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C9127C43217 for ; Thu, 14 Apr 2022 14:13:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345249AbiDNOO3 (ORCPT ); Thu, 14 Apr 2022 10:14:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34368 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346856AbiDNN6C (ORCPT ); Thu, 14 Apr 2022 09:58:02 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7EF26B3691; Thu, 14 Apr 2022 06:48:04 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id DA791B82969; Thu, 14 Apr 2022 13:48:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 279ABC385A1; Thu, 14 Apr 2022 13:48:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649944081; bh=G0+cWBhGlkDwRq7g2a5KVShJa8j5BV2MYaR23cZLkSM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Vz8pzEA1nnenf8y5DOoeFYSaTiWxQlPZ38mfwGkSEduk+1BRM0s2k7XnpNJK5YECr lvJcf+bDPNXg16Q+iyhJdlHm3s0Bi9T6HH7AvKb0++pmB3xped3HLwLtFBfgMTi8bu rF8l53vV5BPmW1l2AvpMGaRPvbILAF47JYNJlO0Q= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Zhou Guanghui , Will Deacon , Sasha Levin Subject: [PATCH 5.4 386/475] iommu/arm-smmu-v3: fix event handling soft lockup Date: Thu, 14 Apr 2022 15:12:51 +0200 Message-Id: <20220414110905.871236885@linuxfoundation.org> X-Mailer: git-send-email 2.35.2 In-Reply-To: <20220414110855.141582785@linuxfoundation.org> References: <20220414110855.141582785@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Zhou Guanghui [ Upstream commit 30de2b541af98179780054836b48825fcfba4408 ] During event processing, events are read from the event queue one by one until the queue is empty.If the master device continuously requests address access at the same time and the SMMU generates events, the cyclic processing of the event takes a long time and softlockup warnings may be reported. arm-smmu-v3 arm-smmu-v3.34.auto: event 0x0a received: arm-smmu-v3 arm-smmu-v3.34.auto: 0x00007f220000280a arm-smmu-v3 arm-smmu-v3.34.auto: 0x000010000000007e arm-smmu-v3 arm-smmu-v3.34.auto: 0x00000000034e8670 watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [irq/268-arm-smm:247] Call trace: _dev_info+0x7c/0xa0 arm_smmu_evtq_thread+0x1c0/0x230 irq_thread_fn+0x30/0x80 irq_thread+0x128/0x210 kthread+0x134/0x138 ret_from_fork+0x10/0x1c Kernel panic - not syncing: softlockup: hung tasks Fix this by calling cond_resched() after the event information is printed. Signed-off-by: Zhou Guanghui Link: https://lore.kernel.org/r/20220119070754.26528-1-zhouguanghui1@huawei.com Signed-off-by: Will Deacon Signed-off-by: Sasha Levin --- drivers/iommu/arm-smmu-v3.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index ef6af714a7e6..02c2fb551f38 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -1708,6 +1708,7 @@ static irqreturn_t arm_smmu_evtq_thread(int irq, void *dev) dev_info(smmu->dev, "\t0x%016llx\n", (unsigned long long)evt[i]); + cond_resched(); } /*